At 10pm Eastern (US) July 28th, on the South-central and Central .58 exp servers, I kept getting cyclical (every 15 sec or so) FPS drops everywhere I went (including far north near Berezhki). I get random drops from 60-70 to 1 about every 10-15 seconds. In town I get the usual 13 fps but with the new 10-15 second intermittent drops to 1.
10-25 people on the servers. Areas could have avg loot or no loot and the problem persisted.